This article examines the current problems in the neorealist theory of international politics and proposes alternatives and operational suggestions. The division between offensive and defensive realism is unnecessary. We need a parsimonious theory that offers greater explanatory power. Therefore, this article proposes the systemic “interaction-structure theory” of stability as an alternative within the materialist tradition of realism. Interaction capacity is both a source of explanation and the precondition for a system. In addition, the offense-defense balance should be viewed as the logic of explanation. This allows the theory to explore mobility, density, and fragmentation as the new independent variables that derive from technology, geography, and power distribution, respectively. Furthermore, the meaning of stability, the dependent variable, should also be expanded to be “the threat to peace” rather than merely the avoidance of war. The name “interaction-structure theory” avoids giving the theory an offensive or defensive label and describes the precise content of this alternative.